Towards the development of a global inventory for black carbon emissions

Abstract

We have developed two global inventories for black carbon (BC) emissions using two distinct methods. The first method uses measured ambient concentration ratios of BC and SO 2 at locations throughout the world. We demonstrate that BC to SO 2 ratios are well correlated at most sites and that distinct ratios of BC to SO 2 apply to source areas from economically distinct regions. However, within any one economic region, the ratio of BC to SO 2 appears to be relatively constant. These facts are used to construct a global inventory of BC emissions by using previously published inventories for the emissions of sulfur. The derived inventory totals nearly 24 Tg C yr −1. The second method uses estimated emission factors and published fuel production and use statistics for wood and bagasse burning, diesel fuel, and domestic and commercial coal use. The combined global emissions using the second method total 12.6 Tg C yr −1. A comparison of the two inventories shows that the estimated emissions from the ratio method are within a factor of two of those derived from emission factors in regions where the data appear to be reliable. The BC inventory from the ratio method is used in the Lawrence Livermore National Laboratory global chemistry/climate model to simulate the world wide distribution of BC. The predicted concentrations are compared with available measurements from throughout the world. This comparison also supports the magnitude of the inventory which we derived from the ratio method to within about a factor of two.